Purpose: This study aims to identify and assess the use of mergers and acquisitions (M&A) performance metrics for small- and medium-sized German pharmaceutical and biotechnology companies. Design/methodology/approach: In depth qualitative interviews with senior key informant executives involved with recent M&A were conducted. Unlike previous studies, the role of the interviews was to identify and uncover the use of a broad set of success metrics to add to a fuller understanding of post-M&A behaviour, leading to a more accurate evaluation of post-M&A performance. Findings: Results from interviews suggest that important M&A success metrics include having a successful organisation, integrated cultures, a high employee retention rate, gaining new technology knowledge, overall economic enhancement, increases in patent-protected products, increases in clinical success rates (perished rate assessment) and increases in the share price. In general, expert interviewees stated that they would use a combination of the success metrics and monetary tools to assess post-M&A success. Originality/value: This study identifies and uncovers a series of different M&A performance success metrics being in prominent use. The use of a combination of metrics is highlighted as being a relatively unique research finding.